The effect of patient age on receipt of adjuvant chemotherapy for node-positive colon cancer: a population-based health data linkage study (#147)
Background: Increasing patient age predicted non-concordance with national treatment guidelines in a state-wide patterns of care study in 2000.1 With the development of Clinical Cancer Registries (ClinCR) in most public hospitals in NSW since 2006, such time- and resource-intensive studies now have the potential to be conducted using routinely collected data. This study assessed whether population-based data linkage could be used to investigate the effect of age on concordance with national guidelines for adjuvant chemotherapy in colon cancer.
Methods: Linkage of the NSW Central Cancer Registry to the NSW Admitted Patients’ Data Collection identified 4,580 patients who underwent surgery for a first colon cancer in 2007 and 2008. 3,273 had a ClinCR record (71.5%). Multiple logistic regression models were used to determine the effect of age on receipt of chemotherapy, after adjusting for potential confounders such as comorbidity, ASA Physical Status, sex, accessibility/remoteness, and socioeconomic disadvantage.
Results: Older age was significantly associated with decreasing likelihood of receiving chemotherapy in 940 patients with lymph-node positive colon cancer (p<0.0001). After adjusting for comorbidity and ASA status, those aged 70-79 (OR 0.25, 95% CI: 0.14-0.46), 80-89 (OR 0.09; 95% CI: 0.05-0.17) and 90+ (OR 0.03; 95% CI: 0.005-0.13) were significantly less likely to receive chemotherapy than those aged less than 60. While the ClinCR is limited to public hospitals, age was still a significant independent predictor in a sensitivity analysis in which all patients with private health insurance were assumed to have received chemotherapy (p<0.0001).
Conclusion: There are continuing age disparities in evidence-based care that are not explained by comorbidities or health status. Further exploration of the reasons for these differences, including the impact of functional status, is needed to improve patient outcomes. Routinely collected clinical data can allow for patterns of care studies to be conducted using record linkage.
- Young et al., MJA 2007; 186(6):292-5